Package io.opentelemetry.sdk.trace.samplers

Class TraceIdRatioBasedSampler

java.lang.Object

io.opentelemetry.sdk.trace.samplers.TraceIdRatioBasedSampler

All Implemented Interfaces:

Sampler

@Immutable
final class TraceIdRatioBasedSampler
extends Object
implements Sampler

We assume the lower 64 bits of the traceId's are randomly distributed around the whole (long) range. We convert an incoming probability into an upper bound on that value, such that we can just compare the absolute value of the id and the bound to see if we are within the desired probability range. Using the low bits of the traceId also ensures that systems that only use 64 bit ID's will also work with this sampler.

Field Summary

Fields

Modifier and Type	Field	Description
private final String	description
private final long	idUpperBound
private static final SamplingResult	NEGATIVE_SAMPLING_RESULT
private static final SamplingResult	POSITIVE_SAMPLING_RESULT

Constructor Summary

Constructors

Constructor	Description
TraceIdRatioBasedSampler(double ratio, long idUpperBound)

Method Summary

Modifier and Type	Method	Description
(package private) static TraceIdRatioBasedSampler	create(double ratio)
private static String	decimalFormat(double value)
boolean	equals(Object obj)
String	getDescription()	Returns the description of this Sampler.
(package private) long	getIdUpperBound()
private static long	getTraceIdRandomPart(String traceId)
int	hashCode()
SamplingResult	shouldSample(Context parentContext, String traceId, String name, SpanKind spanKind, Attributes attributes, List<LinkData> parentLinks)	Called during Span creation to make a sampling samplingResult.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

POSITIVE_SAMPLING_RESULT

private static final SamplingResult POSITIVE_SAMPLING_RESULT

NEGATIVE_SAMPLING_RESULT

private static final SamplingResult NEGATIVE_SAMPLING_RESULT

idUpperBound

private final long idUpperBound

description

private final String description

Constructor Details

TraceIdRatioBasedSampler

TraceIdRatioBasedSampler(double ratio,
 long idUpperBound)

Method Details

create

static TraceIdRatioBasedSampler create(double ratio)

shouldSample

public SamplingResult shouldSample(Context parentContext,
 String traceId,
 String name,
 SpanKind spanKind,
 Attributes attributes,
 List<LinkData> parentLinks)

Description copied from interface: Sampler

Called during Span creation to make a sampling samplingResult.

Specified by:

shouldSample in interface Sampler

Parameters:

parentContext - the parent span's SpanContext. This can be SpanContext.INVALID if this is a root span.

traceId - the TraceId for the new Span. This will be identical to that in the parentContext, unless this is a root span.

name - the name of the new Span.

spanKind - the SpanKind of the Span.

attributes - Attributes associated with the span.

parentLinks - the parentLinks associated with the new Span.

Returns:

sampling samplingResult whether span should be sampled or not.

getDescription

public String getDescription()

Description copied from interface: Sampler

Returns the description of this Sampler. This may be displayed on debug pages or in the logs.

Example: "TraceIdRatioBased{0.000100}"

Specified by:

getDescription in interface Sampler

Returns:

the description of this Sampler.

equals

public boolean equals(@Nullable
 Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

getIdUpperBound

long getIdUpperBound()

getTraceIdRandomPart

private static long getTraceIdRandomPart(String traceId)

decimalFormat

private static String decimalFormat(double value)